Twitter Valued At $11bn Before Potential IPO In 2014

Twitter may already be worth as much as $11 billion - and could be preparing to capitalise by going public in 2014.

That's according to Greencrest Capital, who analyse companies they think are close to floating on the stock exchange.

In report seen by Forbes, Greencrest predicts that Twitter will go public within the next 18-24 months.

Forbes points to hires of new executive managers and refinements to its photo app designed to better place it to compete with Instagram, owned by Facebook.

Greencrest suggests that the secondary market for privately held shares in Twitter value the company at more than $11 billion.

Twitter currently says there are no firm plans for an IPO.

Twitter co-founder and Square CEO Jack Dorsey said it would go public "when we feel the company is ready for that milestone" and not before "as an exit or a goal".

But there are also reasons for concern - both for Facebook and for Greencrest.

In the past 12 months three high-profile tech floatations have failed to match their own hype. Social gaming company Zynga had a strong start but has since lost three quarters of its value.

Meanwhile Facebook has lost 26% of its value since its shares debuted at $38 on the US markets, and Groupon has done even worse, losing about 81% of its value.

And among the companies who had predicted higher values for both Facebook and Zynga was... Greencrest.

In an executive summary of Zynga's investment prospects written in April 2011, eight months before its IPO, Greencrest said the company had "extraordinary value" and expected it to be worth between $15 and $20 billion by the end of 2011. In fact its IPO valued it closer to $7bn - and it is now worth less than $2bn.